This invention relates generally to non-linear amplifiers and more particularly, it relates to a fully differential non-linear amplifier which is responsive to large differential input signals for clipping or clamping its differential output signal to a constant voltage level independent of variations in process and temperature.
In the prior art, there are known non-linear amplifiers of the type in which their outputs are linear for small signal levels and are clipped or clamped to a known voltage level for large signal levels. However, the difficulty encountered with such prior art amplifiers was that the known voltage level at which the clipping or clamping occurred was not constant and varied substantially over process and temperature conditions.
It would therefore be desirable to provide a fully differential non-linear amplifier which has a clipping/clamping voltage level which is substantially constant over all process and temperature conditions. The fully differential non-linear amplifier of the present invention includes four clamping transistors connected in a feedback loop of an operational amplifier. The clamping transistors function as diodes for large input signals so as to clamp the output signal to a constant voltage level.